Testing of swing type check valves using phased array sequence scanning

Abstract

A computer with a proper program generates a phased array sequence of signals. In a pulser with delays, the signals are fed through a multiplexor into a water wedge that is attached to a valve being tested. For a sequential operation of the valves from the open to the closed position, ultrasonic signals are transmitted through the fluid contained in the valve and reflected back through piezo-electric crystals to the multiplexor. By summation and merger of the signals, an image can be developed of the operation of the valve to determine if the valve is operating properly. By use of the water wedge, the top plate of the valve appears to disappear because the water wedge has the same refractive angle as the fluid contained in the valve.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]This invention relates to the non-intrusive testing of valves and, more particularly, to the testing of swing-type check valves using phased array sequence scanning.[0003]2. Brief Description of the Prior Art[0004]In the past, if someone wanted to see if a valve was operating properly flow through the valve was the first thing checked. If more information was desired, the valve could be taken apart. As technology advanced, other ways of checking the internal operation of the valve was developed. For example, a magnetic field may be used to determine the position of the disc in a check valve as is shown in U.S. Pat. No. 5,236,011. Also, ultrasonic vibrations have been used to monitor check valves to determine if they are operating properly. Even a combination of acoustic and magnetic techniques have been used in the past to monitor the operation of valves (see U.S. Pat. No. 5,008,841).[0005]In the past, many different technique...

AI Technical Summary

Problems solved by technology

However, these non-intrusive inspection techniques normally did not give all of the information necessary to determine if a valve is operating properly.

For example, the hinge pin on which the clapper of a check valve operates may be worn over a period of time.

If this condition is not detected before the hinge pin breaks, a catastrophic failure would result.

Typical non-intrusive inspection techniques are not able to detect wear on the hinge pin of a disc-type check valve.

This cannot be done with the inspection techniques that have been developed and used in the past.

Images